changing the orings and the fuel lines wont cause an issue it will purge
when you replace a fuel filter , have the engine warmed up first
fill the new filter as full as possible with fresh diesel or even automatic transmission fluid
install the filter , start the engine and hold the throttle to the floor , the governor will limit the engine rpm to about 3400 rpm
hold it there for a few seconds you will feel the engine start to miss and run rough but hold the throttle until the engine clears and your done
i have seen so many starters burnt down from poor fuel filter replacement procedures it isnt funny , this system works

 

I got a better system. I cut about 7 inches of the fuel line from between the mechanical fuel pump and the fuel filter. I installed a EP8012S electric fuel pump in series with the existing mechanical fuel pump (about $60.00 from AutoZone). Now all I have to do is turn the electric pump on for 1/2 Hour or so and it lights right off. Cheaper than risking a starter or a no start do to air in the system.

 

Ace once you remove the return lines, the fuel may drain off slightly from the IP and filter. This bleed off is what causes the problem with the hard starts.

I should hope it would.....10 seconds should be enough time...... since you put the pump where you did it is not doing it's job well...... those pumps are pushers not pullers. They are normally installed just after the fuel selector valve (Lowest Point) on the inlet line. The manual lift is then usually removed.....our advice is one or the other.

 

I have a switch that I use to control the electric pump. When I need it, it's there. The mechanical pump pushes right through it during normal running. There has been some question if the system is light on pressure at road speed. I can turn the electric on and if performance improves, I know I was running out of fuel. It's there for insurance only.

 

The second day I had my '94 IDI turbo I appearently got some air intrusion. I loosend the "valve" on the bottom of the fuel filter and had my wife crank it over, purged the air and closed it back up , kinda messy but worked.
Is my leak most likely in the filter/assembly or could it be anywhare and just draining back?
I've only had it 3 days but it's started every other time in the 50-60 deg. weather. If my Cummins got air intrusion it was always the aftermarket water seperator/filter I had plumbed up-line from the stock filter/seperator and it would never start until you replaced the filter.
It's wierd that it's only done it to me once, SO FAR. Even wierder is that when it did it it was only sitting for maybe two hours tops. Overnight or durring the work day 8-18 hours it's always started. Again..SO FAR.

 

Your problem could be anywhere. But the typical place was the fuel return lines between the injectors (if painted gray they are original and need replacing). Next place was fuel lines from tank to engine get rusty and let air in but no fuel out of line. I found my problem under a clip holding the fuel line onto the frame.

 

In Case PLC's excellent description was too much to digest all at once , I'll highlight the important part. That holding the throttle down makes a huge difference in cold starting, especially on an older engine or a worn injection pump.

------Robert

 

Well Join the club. I just got my first Diesel too. A 1989 F350 Tow Truck. 7.3 liter IDI. The non turbo-ized version. Regular cab, 5 speed manuel transmission. But that's the correct size of engine that's supposed to be in there, but I was told it was of a different year. I know from researching on the net that they only made it from 1988-1994. Then it turned Powerstroke. It narrows down my years, but no one seems to be able to tell me where the hell is the numbers for the engine block to tell what year the engine is for parts sake. I'm finding some numbers, but not the right ones so far. I have busted down my VIN number to exactly tell me what it all means. Both Plants made and chassis, Incomplete Vehicle, and 4x2 and such. It's interesteing to learn all about it. My next trick is to find out the information about the tow truck body. I found a site or two that gives a break down parts list of tow truck bodies in Pdf formatt. Which is exactly what I want and need. But it sorta looks familiar to mine. Which is a Challanger 4800. But I also have a serial number off of the what looks to be a ID plate on the side of the hydralic filler tank. I can't seem to figure out what that means. Challanger is a current tow truck body provider along with other popular ones as well.

 

Oh yeah it's a duel wheel in the rear. BUt only a 4x2. Which by the way what the heck does that mean, exacltly. Posi traction?

 

4x2 means 4 wheels, 2 driving wheels (2 wheel drive).
That fact that its a duelly kinda screws that definition, but in essence it means only one of the axles is connected to the motor. Duelly's just have extra tires on the drive axle. (at least thats my 2 cents...)

Posi traction would be a limited slip differential.

 

I mean I have a problem if I don't start it for several weeks. When I first got the truck, I drove to North Carolina from Marianna, Florida. About 100 miles out, it shut down. I showed 1/2 tank of fuel. Lucky I had the electric pump with me. I installed it along side the road. Then I figured out that there was something wrong with the pickup in my tank because I can only draw 10 gallons out of the tank. I don't drive this truck very much so I decided to leave the electric pump there just in case. It works like a charm and I don't have to worry about my system bleeding down. For $60.00, it's cheap insurance. It may push better than it pulls, but it does a good job either way.

 

The exact year of the engine is not important when it comes to ordering parts.
In fact external engine parts from an 85 6.9 will fit your 89 7.3 just fine.

I posted this to tell you where the casting numbers are located.

The serial number is located to the right of the IP drive gear cover on the flat portion of the block at the front of the drivers side head.

Block casting........INTERNATIONAL HARVESTER DIESEL ENGINES
6.9L and 7.3L Core Identification

6.9L Old Style Block

Block Casting Number:


On left side of block (beneath oil cooler) 1805440C1
Note: Some 440 blocks are truly new style and must be visually inspected by raised donut around the block heater, frost plug (right rear). Old style below serial number 173828.
Visual Identification: *No counter bored area for block heater
*No defined area on side of block for dip stick
*Thickness of cast iron around block heater 3/8" (.375")
Head Bolts: *7/16, 12 point socket is used to torque head bolts
*Block tapped with 7/16-14 for head bolts

6.9L New Style Block

Block Casting Number: 1807996C1 Note: Some new style blocks have casting
number 440. Above serial number 173828.
Visual Identification: *Has counterbored area for block heater
*Very defined relief area cast in side of block for dip stick tube.
*Thickness of cast iron around block heater 15/32" (.470")
*Latest style (not all new style 6.9) has ribs around head bolts, rear two on left side go from head gasket surface to pan rail - same as 7.3
Head Bolts: *Same as old style 6.9

 

Well I thank YOU! For all and any help that I can get. Around here I have talked with some of the dealerships and they can't seem to help me as of yet. With this new information, I'll get it figured out yet. I also am looking for information on my Wrecker body. I know it's a Challanger 4800. I found a PDF file on one like it, but the tailights and stuff look a different. I heard that there might be a old and new style. Or is a 4800 a 4800 series. Where can I go for a Challanger site to give them my what I think is serial numbers off of the body plate.

 

Sorry this pump is the same type that GM used on the fake diesels they put in their cars (5.7 ). It is a solenoid type that was designed to be mounted on the engine. They are very durable with a hose inlet and hose outlet. the EP80 I mentioned is good for 7 to 12 PSI.

 

Even at the dealership, IDI's are getting to be the forgotten engine.

No computer port to hook the engine diagnostic machine up to, so they have no clue.
Timing? Does it run, if it runs it is OK.

If it don't run, probably the CPS or PCM or HPOP is bad.
Never mind the IDI has none of them.

Yes, even I have been told I had a HPOP problem at a dealer when I was having oil pressure problems with one of my reman engines.
I just laughed and walked out.
Now I only go there for parts, I do all my own engine work for a reason.